1. Field of the Invention
This invention is in the field of pharmaceutical chemistry and therapeutics. More particularly, it relates to concanavalin A materials having immunoregulatory activity and their use in applications where that activity is called for.
2. Prior Art
Concanavalin A (CA) is a well characterized plant lectin that reacts with numerous cell types and various molecules of the mammalian immune system. The cummulative effect of these reactions is often unpredictable, since CA has been shown both to stimulate and to suppress the immune system in in vitro and in vivo tests. Further complicating an understanding of these diverse biological effects is CA's molecular heterogeneity. Solutions of CA are mixtures of varying proportions of multimolecular aggregates, tetramers, dimers, monomers and free and associated monomer fragments. The exact composition of this mixture is dependent upon the preparation scheme and the type of handling the particular sample has received. H. Markowitz and colleagues reported in SCIENCE, 163, 476, that the CA mixture provided immunosuppressive activity in grafts in mice. R. Weil, III and colleagues reported at TRANSPLANTATION, 17, No. 6 600, (1974) the use of CA to increase rat heart allograft survival.
A variety of CA derivatives are described in the literature. These include succinylated CA, or SCA; acetylated CA or ACA; cross-linked CA; hybrid CA; and the reaction product of CA with maleic anhydride, etc. With any of these materials, there is a need to provide reprodcibility in composition and a need to optimize the desired activity while minimizing side effects and toxicity.